Ratchet tool

Abstract

A ratchet tool is provided. The ratchet tool includes a body having a head and an elongated handle. A gear train and pawl assembly are contained within the head of the body. A switching mechanism also extends into the head of the body and interacts with the pawl assembly. The arrangement and interaction of the body, gear train, pawl assembly and switching mechanism provides for transmission of torque from the ratchet tool in a single direction when the handle is rotated both in clockwise and counterclockwise directions.

1. A ratchet tool comprising:
 a body including a head and a handle, said head having a cavity formed therein, said head further having an axis defined therethrough, said handle having an end fixed relative to said head, said handle defining a length extending away from said head, said handle being oriented with said length substantially perpendicular to said axis; 
 a gear train disposed within said cavity, said gear train including first and second gears pivotally supported about said axis and a gear coupling disposed between said first and second gears, said gear coupling transmitting rotation of one of said first and second gears to an opposite rotation of the other of said first and second gears; 
 a socket drive fixed relative to said second gear and extending outside of said head; 
 a pawl assembly disposed within said cavity outside of said gear train, said pawl assembly including a first pawl adapted to mesh with said first gear and a second pawl adapted to mesh with said second gear, said pawl assembly further including a pivot member and a pair of push arms disposed between said first and second pawls, said push arms pivotally coupling said first and second pawls about said pivot member, said pawl assembly being movable between first and second configurations, said first configuration including said first pawl pivoted into engagement with said first gear and said second pawl correspondingly pivoted away from said second gear, said second configuration including said second pawl pivoted into engagement with said second gear and said first pawl correspondingly pivoted away from said first gear; and 
 a switching mechanism extending into said cavity and engaging said pawl assembly, said switching mechanism being selectively fixed in a first position relative to said body, said switching mechanism applying a first force to said pawl assembly to move said pawl assembly to said first configuration when said handle is rotated about said axis in a first direction, said switching mechanism applying a second force to said pawl assembly to move said pawl assembly to said second configuration when said handle is rotated about said axis in a second direction opposite to said first direction. 
 
   
   
     2. The ratchet tool of  claim 1 , wherein said first gear has a spur gear portion and a pinion gear portion, said spur gear portion being larger than said pinion gear portion, said spur gear portion including a plurality of teeth extending outwardly therefrom, said pinion gear portion including a plurality of teeth extending outwardly therefrom. 
   
   
     3. The ratchet tool of  claim 2 , wherein said first pawl defines a concave engaging side having a plurality of teeth extending therefrom, said teeth of said concave engaging side being complementary to said teeth of said spur gear portion. 
   
   
     4. The ratchet tool of  claim 3 , wherein said teeth of said spur gear portion and said teeth of said concave engaging side are straight in shape. 
   
   
     5. The ratchet tool of  claim 2 , wherein said second gear has a generally annular shape and defines an outer circumferential surface and an inner circumferential surface, said outer circumferential surface having a plurality of teeth extending outwardly therefrom, said inner circumferential surface having a plurality of teeth extending inwardly therefrom. 
   
   
     6. The ratchet tool of  claim 5 , wherein said second pawl defines a concave engaging side having a plurality of teeth extending outwardly therefrom, said teeth of said concave engaging side being complementary to said teeth of said outer circumferential surface. 
   
   
     7. The ratchet tool of  claim 6 , wherein said teeth of said outer circumferential surface and said teeth of said concave engaging side are straight in shape. 
   
   
     8. The ratchet tool of  claim 5 , wherein gear coupling includes a plurality of idler gears, said idler gears each having a plurality of teeth extending outwardly therefrom complementary to said teeth of said pinion gear portion and said teeth of said inner circumferential surface. 
   
   
     9. The ratchet tool of  claim 8 , wherein said idler gears are disposed within and engaged with said inner circumferential surface of said second gear, said idler gears being spaced apart from each other, said pinion gear portion extending between and engaging said idler gears. 
   
   
     10. The ratchet tool of  claim 8 , wherein said teeth of said idler gears, said teeth of said pinion gear portion, and said teeth of said inner circumferential surfaces are involute in shape. 
   
   
     11. The ratchet tool of  claim 5 , wherein said spur gear portion of said first gear is substantially similar in size to said outer circumferential surface of said second gear. 
   
   
     12. The ratchet tool of  claim 1 , wherein each of said first and second pawls define a concave gear engaging side and a switching side opposite said concave gear engaging side, said switching side of said first pawl having a notch defined therein at a generally central portion thereof, said switching side of said second pawl having a protrusion extending therefrom at a generally central portion thereof corresponding with said notch of said first pawl. 
   
   
     13. The ratchet tool of  claim 12 , wherein said switching mechanism includes an elongate switch arm engaging said switching sides of said first and second pawls proximate said notch and said protrusion. 
   
   
     14. The ratchet tool of  claim 13 , wherein said elongate switch arm has a substantially rectangular cross section, said notch defining a substantially square corner complementary to said elongate switch arm, said protrusion defining a substantially square corner complementary to said elongate switch arm. 
   
   
     15. The ratchet tool of  claim 1 , further comprising a pair of separation plates disposed within said cavity between said first and second gears and between said first and second pawls. 
   
   
     16. The ratchet tool of  claim 1 , further comprising a top cover supporting said switching mechanism, said top cover extending over said cavity and engaging said head. 
   
   
     17. The ratchet tool of  claim 1 , wherein said switching mechanism is selectively fixed in a second position relative to said body, said switching mechanism applying a third force to said pawl assembly to move said pawl assembly to said second configuration when said handle is rotated about said axis in said first direction, said switching mechanism applying a fourth force to said pawl assembly to move said pawl assembly to said first configuration when said handle is rotated about said axis in said second direction.